Update revision to 19.

Change-Id: I55dbae0a2da6435146fbe7c69fc7f6c091194e8c
diff --git a/build.gradle b/build.gradle
index 77cff72..6a90344 100644
--- a/build.gradle
+++ b/build.gradle
@@ -10,7 +10,7 @@
 }
 
 ext.supportVersion = '23.0.1'
-ext.extraVersion = 18
+ext.extraVersion = 19
 ext.supportRepoOut = ''
 ext.buildToolsVersion = '22.1.0'
 ext.buildNumber = Integer.toString(ext.extraVersion)